The present invention relates to a microwave oven including a plurality of magnetrons and, more particularly, to a fault condition alarm system for indicating an alarm condition when at least one magnetron is placed in a fault condition.
There is a microwave oven which includes a plurality of magnetrons for cooking purposes. Now assume that the microwave oven includes n-number of magnetrons, each magnetron developing microwave energy of A watts. In such a microwave oven, if one magnetron is placed in a fault condition and does not operate, the total output energy becomes ##EQU1## Accordingly, the cooking operation is not performed in a desired manner.
Accordingly, an object of the present invention is to provide an alarm system for indicating magnetron fault condition in a microwave oven including a plurality of magnetrons.
Another object of the present invention is to stabilize an operation mode of a microwave oven including a plurality of magnetrons.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a control system is provided for activating an alarm lamp when at least one magnetron is placed in a fault condition. The fault condition alarm display is continuously maintained even when a cooking operation is completed, whereby the operator can recognize the fault and lengthen the cooking period of the cooking operation.
In such an alarm system, there is a possibility that the control system erroneously detects the fault condition when the oven door is opened during cooking even though the magnetrons are in the normal operation mode. The above-mentioned erroneous detection is caused by a time delay between the opening of the oven door and the actuation of a door switch. The present control system includes a logic circuit for detecting existence of an actual fault condition.